.458 Lott
The .458 Lott is a dangerous game hunting cartridge developed in the United States by Jack Lott. History The .458 Winchester Magnum became an immediate commercial success when it was introduced in 1956, having proven to be a more economical alternative to the expensive British double rifles that were considered a standard for hunting big game in Africa. It promised to emulate the performance of the .450 Nitro Express in the type of cartridge designed for bolt-action rifles. However, it was soon realized that the cartridge was not performing as anticipated, as several factors contributing to its less-than-ideal performance in Africa were made apparent; clumping of its compressed powder charge and usage in 20 to 22 inch (510 to 560mm) barrel rifles. Big game hunter and firearms writer Jack Lott had an adverse encounter in Mozambique with an African Cape buffalo, where he got injured. At the time, he had been hunting with a rifle chambered in the then-new .458 Winchester Magnum. This incident had convinced Lott that a cartridge more powerful than the .458 Winchester Magnum would be needed to hunt dangerous game. After the encounter, Lott began searching for a big bore hunting cartridge that would suit his needs perfectly. Not finding the fitting cartridge, Lott designed a cartridge which he felt would fit his requirements in a big game hunting cartridge. The original drawings were done on a paper napkin at a diner. The first cases for the new cartridge were fireformed from .375 H&H Magnum brass into a chamber using .458 caliber bullets whose bases were resized to .375 inches in order to fit into the mouth of the .375 H&H Magnum. This fireforming method left the newly formed cases slightly shorter than the parent cases. The resulting cartridge was named .458 Lott in his honor. A similar process was used by David Miller and Curt Crum to create cases for their early custom .458 rifles. The making of the cases began by casting a .458 inch (11.6 mm) bullet with a .375 inch (9.5 mm) shank and weighing around 260 grains. This bullet was then seated on a .375 H&H Magnum case that contains 30.0 grains (1.94 grams) of Hercules 2400 powder with some polyester material used as a wadding to hold the powder charge against the primer. This set-up was then fireformed in a rifle with a .458 Lott chamber. The fireformed cases were then run through a .458 Winchester Magnum full length re-sizing die with a set off of .125 inches (3.2 mm). Once this was accomplished, the cases were trimmed to 2.790 in (70.9 mm) tumbled clean. Sadly for Miller and Crum, this method of fireforming of brass led to severe gas cutting into the neck area of the .458 Lott fireforming rifle after only 200 rounds. In 1989, A-Square became the first manufactuer to offer the .458 Lott as a commercial cartridge. In 1995, they had also championed the successful SAAMI standardization of the .458 Lott. Design Details The .458 Lott is designed to address the problems presented by the .458 Winchester Magnum cartridge, by boasting a higher case capacity to provide better performance and less compression of the powder charge. The .458 Lott achieved this with its length. Moreover, as it is essentially a longer version of the .458 Winchester Magnum, converting the .458 Winchester Magnum to .458 Lott involves, in many cases, a simple re-boring of the chamber, and if required, a lengthening of the magazine. It was standardized in 1995 by SAAMI based on specifications provided by Arthur Alphin and A-Square LLC. According to Alphin, the cartridge length was standardized at 2.8 inches (71.1mm) because of many converted rifles in the field that were chambered for the original Jack Lott length. The specs published by SAAMI reflect this fact. The specifications call for a cartridge that gradually tapers. However, A-Square and a few other manufacturers provide a ghost shoulder in the cartridge, that which is not included in the specification as standardized by SAAMI. Alphin chose not to include the ghost shoulder to stay true to Jack Lott's wishes and to honor his memory. The ghost shoulder served to provide better retention of the bullet in the case under recoil. Barnes' .458 Lott loads, like those of A-Square's, feature a ghost shoulder for this very same reason. Designed to provide more velocity than the .458 Winchester Magnum, the .458 Lott does not just match but exceed the former's original performance specifications. It is capable of firing a 500 grain (32 grams) bullet at 2,300 feet per second (700 meters per second) from a 23-inch barrel, such as that of the Ruger M77. This performance figure easily exceeds that which is expected from the .450 Nitro Express and .458 Winchester Magnum. The .458 Lott is considered to be a better cartridge for hunting dangerous African game than the .470 Nitro Express when judged by its effect on big game. Because of its development and purpose, the .458 Lott's performance is often compared to that of the .458 Winchester Magnum. This is inevitable, as the latter was what the .458 Lott was intended to replace. It is able to attain a 2,300 ft/s velocity rating with a 500 grain jacketed bullet at safe pressure levels from a 23 to 24 inch barrel. This is compared to many manufacturers that load the .458 Winchester Magnum to velocity ratings between 1,950 and 2,050 ft/s, with the exception of Hornady's Superformance ammunition, which uses proprietary powder loads. The .458 Lott can reach a muzzle velocity of 2,150 ft/s with a 600 grain bullet, much greater than that reached by the Superperformance .458 Winchester ammunition. With lighter 300 grain bullets, the .458 Lott can achieve a muzzle velocity of 2,850 ft/s. These energy and velocity figures provide the .458 Lott a 50 to 100 yard gain over the .458 Winchester Magnum in distance. This level of performance increase provides superior penetration and stopping power to the .458 Winchester Magnum against dangerous game. The monometal bullets, however, fall short of this velocity threshold, due to the need to seat them deeper owing to their length and the need to stay within the maximum overall length specification of the cartridge. This is because the lower monometal bullets have a higher length-to-weight ratio than conventional bullets. Manufacturers such as A-Square have chosen to load slightly lighter 465 grain (30.1 grams) bullets instead of the 500 grain (32 grams) projectiles. The .458 Lott's straight tapered case provides greater flexibility in reloading to lower muzzle velocities than bottlenecked cartridges. The ability to reload ammunition to lower velocities with lighter projectiles can provide shooters with ammunition that has less recoil than full-powered .458 Lott loads. Big bore cartridge manufacturer Nyati, Inc. took advantage of this flexibility, offering ammunition with a 500 grain copper jacketed bullet at a muzzle velocity of 1,100 ft/s, also offering intermediate-power loads for the .458 Lott, as well. Handloaders can make use of the wide variety of projectiles of useful weights in .45 caliber for the .458 Lott cartridge. Bullets ranging from 300 to 600 grains in weight can be loaded for the cartridge. Combined with the ability to load the cartridge to lower power levels, easily adds to the .458 Lott's versatility. Velocities range from 2,150 ft/s with 600 grain bullets to 3,000 ft/s with 300 grain bullets. Spitzer bullets with superior ballistics such as the Barnes X or TSX bullet provide better down range performance over conventional .45 caliber bullets. The .458 Lott does great with hard cast lead bullets, with which it can be loaded to the power level of the original .45-70 Government cartridge, which used a 405 grain bullet at a muzzle velocity of 1,330 ft/s. While lacking in velocity and muzzle energy when compared to the .450 Rigby or the .460 Weatherby Magnum, the .458 Lott makes up for it by virtue of its versatility. Larger volume cases such as the .460 Weatherby Magnum do not do well with lower powder charges below the recommended minimums, due to erratic ignition and hangfire issues experienced when large capacity cartridges are loaded with small powder charges. In contrast, the .458 Lott does well with lower powder charges. Criticism There has been some criticism directed towards the cartridge for its inability to reach the so-called magical 2,300 to 2,400 ft/s velocity that some big game hunters believe is required for maximum penetration on dangerous game animals. As a result, no scientific proof has been made on this subject, and it is likely accepted because of older bullets that are unable to retain their weight at high velocity. This is a particular worry outside of North America where only particular lines of cartridge powders are available. Even though the Lott can reach this velocity, the powders used may not be available in most locales. This is quite true in many African nations. In South Africa, where the local Denel Somchem powders are readily available, none of the powders could launch a 500 grain bullet at 2,300 ft/s. This lead to the development of the .458 Express cartridge by Dr. Koos Badenhorst. The new design uses a 3 inch cartridge made from basic .458 brass based on the .375 H&H Magnum casehead. The case provided the necessary capacity for using Somchem powders such as S321 and S335 to drive 500 grain projectiles to a muzzle velocity of 2,300 ft/s. External Links *Wikipedia article *.458 Lott at Municion.org (Spanish) Category:Ammunition Category:Commercial cartridges